Process of treating tellurid ores of gold and silver.



No; 739,138. I PATENTED SEPT. 15, 1903.

' G. E. BAKER & A. W. BURWELL.

PROCESS OF TREATING TELLURID ORES OF-GOLD-AND SILVER;

APPLICATION FILED NOV.11, 1902.

no MODEL.

Witnesses 150 6 7796072: M 4425/ ma NORRIS Perms co. PHOTO-LITHQ, WAsmMr-Yufl, a. 6.

U ITED STATES Patented September 15, 1909;. A

PATENT OFFICE.

CHARLES E. BAKER AND ARTHUR W. RURWELL, or CLEVELAND, OHIO.

PROCESS OF TREATING TELLURlD ORES OF GOLD AND SILVER.

SPECIFICATION forming part of Letters Patent No. 73951 38, dated September 15, 1903'.

Appli'oatibn filed November 11,1902.

Serial No. 130.844. (No specimens.)

and ARTHUR W. BURWELL, citizens of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio,'have invented certain new and useful Improvements in Processes of Treating Tellurid Ores of Gold and Silver, of which the following is a specification.

This process is especially intended for the recovery ofgold and silverfrom their tellurid ores. These ores generally contain base metals- -such as iron, copper, zinc, or lead' but not in paying quantities.

The process,"generally stated, consists in treating raw crushed oreor concentrates with chlorin while subjected to a temperature suflicient to cause the chlorin to combine with the tellurium to produce a soluble chlorid. The base metals present also combine with chlorin to form soluble protochlorids. The gold is liberated in a free state and the silver is converted into a chlorid. To obtain the best results, both the ore and chlorin should be dry and the ore should be agitated to increase the speed of the reaction. Waterv is then added to the mass, whereby the basemetal chlorids are brought into solution, while the free gold and silver chlorid remain with the gangue and may be separately recovered.

The process may be carried out by the use of any suitable apparatus. One which has been employed is shown in the accompanying drawing, in which- The figure is a vertical longitudinal section showing the ore-drum in elevation.

The apparatus shown comprises a revolving drum 1, preferably of boiler-iron lined with porcelain. This drum has hollow trunnions 2 3, also lined withporcelain, which are supported in journal-boxes 1, carried by standards 5. A gear-wheel 6 for rotating the drum is secured on trunnion 3. The drum has a suitable opening 7 for receiving and discharging its contents. Surrounding the drum is a chamber 8, which may be of boileriron 9 with a covering 10 of asbestos. A flue 11 opens into chamber 8 at one end and near its base, serving for the introduction of heating-gases. A flue 12 for discharging the I waste gases leads from the other end of the chamber near its top. A door 13in one sideof the chamber gives access to the drum for the purpose of charging and discharging it.

For the sake of illustration the process will be described ascarried out on a tellurid ore containing gold, silver, and iron. The ore is crushed to about fifty mesh, and a suflicient amount is placed in the drum to one-third fill it. The drum is now set in rotation and its. contents heated to about 150 centigrade preferably by waste products of combustion introduced through flue 11. Dry chlorin gas is then introduced through trunnion 2 and combines with the tellurium or the greater part thereof to form a soluble chlorid. The

' iron or other base metal in the oreis thus converted into a protochlorid, and care must be takento discontinue the introduction of chlo rin gas at the precise moment when all of the telluriu-In has been remov ed,which can be de termined by the fact that chlorin only then escapes through trunnion 3. This is necessary to prevent conversion of the ferrous chlorid into the more volatile ferric chlorid, which might be driven off by the heatapplied to the drum. The mass is now treated with water, either in the drum or in a separate vessel, whereby the iron or other base-metal chlorid and the tellurium chlorid are brought into solution, while the free gold and the silver chlorid remain with the gangue. The gold and silver may be recovered by amalgamation. A small amount of acid, preferably dilute sulfuric acid, must be used in amalgamation to prevent fiouring of the mercurya result which seems to be due to the presence of tellurium compounds in the solution. The pulpis preferably heated during the amalgamation, as by the use of steam. If any gold goes into solution as chlorid, it maybe recovered by electrolysis, using a voltage insufficient to decompose the base-metal chlorid. The basemetal chlorid solution is preferably electrolyzed with insoluble anodes to give chlorin for use in the process and the metal. When iron is thus recovered, it may be briqueted and melted down.

We claim 1. The process of treating ores of gold and silver containing a base metal and tellurium,

which consists of combining the base metal and tellurium with chlorin, and separating the base-metal chlorid from the other metals or metallic compounds in the mass, as set forth.

2. The process of treating ores of gold and silver containing a base metal and tellurinm, which consists of combining the base metal and tellurium with chlorin by bringing chlorin into contact with the ore while hot, and separating the base-metal chlorid from the other metals or metallic compounds in the mass, as set forth.

3. The process of treating ores of gold and silver containing a base metal and tellurinm, which consists of combining the base metal and tellurium with chlorin by bringing dry chlorin into contact with the dry ore while hot,

and separating the base-metal chlorid from.

the other metals or metallic compounds in the mass, as set forth.

4. The process of treating ores of gold and silver containing a base metal and tellurinm, which consists of combining the base metal and tellurium with chlorin, and dissolving and removing the base-metal and tellurium chlorids from the'mass, as set forth.

5. The process of treating ores of gold and silver containing a base metal and tellurinm, which consists of combining the base metal and tellurium with chlorin, dissolving and removing the base-metal and tellurium chlorids from the mass, and electrolyzing the base- CHARLES E. BAKER. ARTHUR W. BURWELL.

Witnesses:

A. O. BOWEN, S. E. STONE. 

